The Doe Run Company has announced the closure of its primary lead smelting plant in Herculaneum, Missouri. This is due to the 2008 change in the National Ambient Air Quality Standard for lead. The allowable amount was reduced to one tenth of the previous level. The original acceptable levels were from 1.5 µg/m3 (micrograms of lead per cubic meter of air) to 0.15 µg/m3.
The smelting plant will close on December 31, 2013. This is the last primary lead smelting plant in the United States that has the ability to smelt raw lead ore. The Herculaneum smelting plant has been in operation for over 100 years, since opening in 1892. 218 people will lose their jobs because of the closure.
Doe Run has already spent millions of dollars in upgrades to meet the tightening levels up to and including the 1.5 µg/m3 levels. In order to reduce to one-tenth (1/10) of that level, the costs necessary would be prohibitive. Executives at the Doe Run Company calculated that trying to meet the new standards of 0.15 µg/m3 would not make any business sense.
They have developed a new process of refining the lead ore that does not use the smelting process. It uses chemicals and electricity. The call the new process electrowinning which they were testing in 2010. They also calculated the cost of making a large-scale plant capable of processing the current quantities of lead using the new technology, but were not able to scale up the process and still be able to turn a profit on the lead.
The adoption of the new process would dramatically reduce the lead and sulfur dioxide emissions. In a press release, Doe Run said “In 2012, we announced that the cost to build a comparably-sized electrowinning plant was too great for our company, given the present economic conditions and other demands on our operations. We continue to pursue opportunities to bring this technology to commercialization, perhaps on a smaller scale.”
Since more than 80% of all the lead mined in the United States goes towards batteries for automotive, alternative energy storage and UPS units, we can expect those items to increase in price as the ore will be shipped to China to be smelted.